Tim Cook, who's run Apple since taking over from co-founder Steve Jobs in 2011, probably doesn't expect to be in the room himself for another 15 years. While the tech giant's CEO has given no indication of an imminent transition, he's made it clear he wants his heir to come from within the company so he can serve as a mentor. The central candidate is John Ternus, senior vice president for hardware engineering, who oversees development of the devices that generate roughly 80% of Apple's revenue. At 50, Ternus is also younger than many of the company's other senior leaders, meaning he could be in the top job longer. Bloomberg News Managing Editor for Global Consumer Tech Mark Gurman joins Bloomberg Businessweek Daily to discuss. He speaks with Carol Massar and Tim Stenovec.